---
type: reference, howto
stage: Secure
group: Composition Analysis
info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/product/ux/technical-writing/#assignments
---

# License scanning of CycloneDX files **(ULTIMATE)**

> - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/384932) in GitLab 15.9 for GitLab SaaS [with two flags](../../../administration/feature_flags.md) named `license_scanning_sbom_scanner` and `package_metadata_synchronization`. Both flags are disabled by default and both flags must be enabled for this feature to work.
> - [Enabled](https://gitlab.com/gitlab-org/gitlab/-/issues/385173) in GitLab 15.10 for GitLab SaaS.
> - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/385173) in GitLab 15.10 for self-managed GitLab [with two flags](../../../administration/feature_flags.md) named `license_scanning_sbom_scanner` and `package_metadata_synchronization`, both of which must be enabled for this feature to work. The flags are disabled by default due to the initial performance load when the license database is first imported. Work to improve performance is being tracked in [issue 397670](https://gitlab.com/gitlab-org/gitlab/-/issues/397670).
> - [Enabled](https://gitlab.com/gitlab-org/gitlab/-/issues/385173) in GitLab 15.11 for self-managed GitLab.

To detect the licenses in use, License Compliance relies on running the
[Dependency Scanning CI Jobs](../../application_security/dependency_scanning/index.md),
and analyzing the [CycloneDX](https://cyclonedx.org/) Software Bill of Materials (SBOM) generated by those jobs.
Other 3rd party scanners may also be used as long as they produce a CycloneDX file with a list of dependencies for [one of our supported languages](#supported-languages-and-package-managers).
This method of scanning is also capable of parsing and identifying over 500 different types of licenses, as defined in [the SPDX list](https://spdx.org/licenses/).
Licenses not in the SPDX list are reported as "Unknown". License information can also be extracted from packages that are dual-licensed, or have multiple different licenses that apply.

## Enable license scanning

Prerequisites:

- On GitLab self-managed only, enable [Synchronization with the GitLab License Database](../../../administration/settings/security_and_compliance.md#choose-package-registry-metadata-to-sync) in Admin Area for the GitLab instance. On GitLab SaaS this step has already been completed.
- Enable [Dependency Scanning](../../application_security/dependency_scanning/index.md#configuration)
  and ensure that its prerequisites are met.

From the `.gitlab-ci.yml` file, remove the deprecated line `Jobs/License-Scanning.gitlab-ci.yml`, if
it's present.

## Supported languages and package managers

License scanning is supported for the following languages and package managers:

<!-- markdownlint-disable MD044 -->
<table class="supported-languages">
  <thead>
    <tr>
      <th>Language</th>
      <th>Package Manager</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>.NET</td>
      <td rowspan="2"><a href="https://www.nuget.org/">NuGet</a></td>
    </tr>
    <tr>
      <td>C#</td>
    </tr>
    <tr>
      <td>C</td>
      <td rowspan="2"><a href="https://conan.io/">Conan</a></td>
    </tr>
    <tr>
      <td>C++</td>
    </tr>
    <tr>
      <td>Go</td>
      <td><a href="https://go.dev/">Go</a></td>
    </tr>
    <tr>
      <td rowspan="2">Java</td>
      <td><a href="https://gradle.org/">Gradle</a></td>
    </tr>
    <tr>
      <td><a href="https://maven.apache.org/">Maven</a></td>
    </tr>
    <tr>
      <td rowspan="3">JavaScript and TypeScript</td>
      <td><a href="https://www.npmjs.com/">npm</a></td>
    </tr>
    <tr>
      <td><a href="https://pnpm.io/">pnpm</a></td>
    </tr>
    <tr>
      <td><a href="https://classic.yarnpkg.com/en/">yarn</a></td>
    </tr>
    <tr>
      <td>PHP</td>
      <td><a href="https://getcomposer.org/">Composer</a></td>
    </tr>
    <tr>
      <td rowspan="4">Python</td>
      <td><a href="https://setuptools.readthedocs.io/en/latest/">setuptools</a></td>
    </tr>
    <tr>
      <td><a href="https://pip.pypa.io/en/stable/">pip</a></td>
    </tr>
    <tr>
      <td><a href="https://pipenv.pypa.io/en/latest/">Pipenv</a></td>
    </tr>
    <tr>
      <td><a href="https://python-poetry.org/">Poetry</a></td>
    </tr>
    <tr>
      <td>Ruby</td>
      <td><a href="https://bundler.io/">Bundler</a></td>
    </tr>
    <tr>
      <td>Scala</td>
      <td><a href="https://www.scala-sbt.org/">sbt</a></td>
    </tr>
  </tbody>
</table>
<!-- markdownlint-disable MD044 -->

The supported files and versions are the ones supported by
[Dependency Scanning](../../application_security/dependency_scanning/index.md#supported-languages-and-package-managers).

## License expressions

GitLab has limited support for [composite licenses](https://spdx.github.io/spdx-spec/v2-draft/SPDX-license-expressions/).
License compliance can read multiple licenses, but always considers them combined using the `AND` operator. For example,
if a dependency has two licenses, and one of them is allowed and the other is denied by the project [policy](../license_approval_policies.md),
GitLab evaluates the composite license as _denied_, as this is the safer option.
The ability to support other license expression operators (like `OR`, `WITH`) is tracked
in [this epic](https://gitlab.com/groups/gitlab-org/-/epics/6571).

## Blocking merge requests based on detected licenses

Users can require approval for merge requests based on the licenses that are detected by configuring a [license approval policy](../license_approval_policies.md).

## Running in an offline environment

For self-managed GitLab instances in an environment with limited, restricted, or intermittent access to external resources through the internet, some adjustments are required to successfully scan
CycloneDX reports for licenses. For more information, see the offline [quick start guide](../../../topics/offline/quick_start_guide.md#enabling-the-package-metadata-database).

## Troubleshooting

### A CycloneDX file is not being scanned and appears to provide no results

Ensure that the CycloneDX file adheres to the [CycloneDX JSON specification](https://cyclonedx.org/docs/latest/json). This specification does [not permit duplicate entries](https://cyclonedx.org/docs/latest/json/#components). Projects that contain multiple SBOM files should either report each SBOM file up as individual CI report artifacts or they should ensure that duplicates are removed if the SBOMs are merged as part of the CI pipeline.

You can validate CycloneDX SBOM files against the `CycloneDX JSON specification` as follows:

```shell
$ docker run -it --rm -v "$PWD:/my-cyclonedx-sboms" -w /my-cyclonedx-sboms cyclonedx/cyclonedx-cli:latest cyclonedx validate --input-version v1_4 --input-file gl-sbom-all.cdx.json

Validating JSON BOM...
BOM validated successfully.
```

If the JSON BOM fails validation, for example, because there are duplicate components:

```shell
Validation failed: Found duplicates at the following index pairs: "(A, B), (C, D)"
#/properties/components/uniqueItems
```

This issue can be fixed by updating the CI template to use [jq](https://jqlang.github.io/jq/) to remove the duplicate components from the `gl-sbom-*.cdx.json` report by overriding the job definition that produces the duplicate components. For example, the following removes duplicate components from the `gl-sbom-gem-bundler.cdx.json` report file produced by the `gemnasium-dependency_scanning` job:

```yaml
include:
  - template: Jobs/Dependency-Scanning.gitlab-ci.yml

gemnasium-dependency_scanning:
  after_script:
    - apk update && apk add jq
    - jq '.components |= unique' gl-sbom-gem-bundler.cdx.json > tmp.json && mv tmp.json gl-sbom-gem-bundler.cdx.json
```
